Various shaped blocks or elongate pieces of solid thermoplastic material are adapted to be fed into devices adapted to receive, melt and dispense molten thermoplastic material from the elongate pieces. Generally such devices comprise a barrel member having an internal melting chamber which communicates with an outlet opening through a nozzle, and a sleeve with a through opening having one end secured to the barrel member with its through opening communicating with the end of the melting chamber opposite the nozzle. The elongate piece of solid thermoplastic material is adapted to fit closely within the through opening in the sleeve, with one end portion of the elongate piece in the melting chamber and the other end portion projecting through the sleeve. Means are provided for heating the barrel member to melt the end portion of the elongate piece of thermoplastic material therein, and the device affords pressing the elongate piece through the sleeve and into the melting chamber to force molten thermoplastic material out of the melting chamber through the nozzle, which with some devices is done with the thumb of a user's hand, and in other devices is done through an automated or manually actuated feed means included in the device.